That is only TODAY, not after Finland formally joining NATO.Finland is not a threat to Russia. Finnish is an Uralic language. Russian is mainly Uralic. Moskva is an Uralic word. Finland only has a few million people and Finland is de facto a NATO country. They use F-18.
Finland as of today is not a threat to Russia even if it uses F-18. Finland after joining NATO will be a front line threat to Russia. Being official member of NATO obliges Finland to attack Russia if any conflict happens between Russia and another NATO member. Finland as of today does not have to do so even if it has close relationship with NATO.
Officially joining NATO does not necessarily prevent Russia attacking Finland if Russia felt a serious chance of conflict. Remember 1979 Sino-Vietnamese war, China invaded Vietnam after Vietnam signed a friendship and cooperation treaty with USSR in October 1978. At the time, the treaty's detailed texts were not published, so nobody knows if the treaty obliged USSR to militarily assist Vietnam in case of such war. China invaded Vietnam anyway. Why? 1. test the true nature of the treaty. 2. Call the USSR's bluff. This can happen to Finland too. Any ways, it was the Vietnamese paid the high cost. It is certainly Finland going to pay the cost if history repeats itself.
It is a extremely stupid move by the Finnish politician (and Swedish as well) to acquire more security by increasing the risk of loosing security. It is like gambling in a volatile stock market with one's whole pension saving.